Multi-channel signal encoding method, multi-channel signal decoding method, encoder, and decoder

Abstract

To provide a multi-channel signal encoding method and a multi-channel signal decoding method that improve encoding efficiency.SOLUTION: A method comprises: determining reverberation gain parameters corresponding to a down-mix signal of a first channel signal and a second channel signal in a multi-channel signal, and different subbands of the first channel signal and the second channel signal (310); determining a target reverberation gain parameter which needs to be encoded within the reverberation gain parameters corresponding to the different subbands of the first channel signal and the second channel signal (320); generating parameter indication information (330); using the parameter indication information to indicate the subband corresponding to the target reverberation gain parameter (330); and encoding the target reverberation gain parameter, the parameter indication information and the down-mix signal so as to generate a bit stream (340).SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] This application claims the priority of Chinese Patent Application No. 201710236773.3, filed with the China National Intellectual Property Administration on April 12, 2017, and entitled "MULTI-CHANNEL SIGNAL ENCODING METHOD, MULTI-CHANNEL SIGNAL DECODING METHOD, ENCODER, AND DECODER", which is incorporated herein by reference in its entirety.

[0002] This application relates to the field of audio coding, and more particularly, to multi-channel signal encoding methods, multi-channel signal decoding methods, encoders, and decoders.

Background Art

[0003] As the quality of life improves, people are demanding higher-quality audio. Compared with monaural audio, stereo audio realizes a sense of direction and distribution for each sound source, and realizes improved clarity, intelligibility, and a sense of live sound. Therefore, stereo audio is very popular.

[0004] Stereo processing technologies mainly include mid / side (Mid / Sid, MS) encoding, intensity stereo (IS) encoding, and parametric stereo (PS) encoding.

[0005] In the prior art, when PS encoding is used to encode a multi-channel signal, on the encoder side, it is necessary to calculate the reverberation gain parameters corresponding to each sub-band of the channel signal and encode the reverberation gain parameters corresponding to each sub-band of the channel signal. As a result, on the decoder side, reverberation processing can be performed on each sub-band of the channel signal based on the reverberation gain parameters corresponding to each sub-band of the channel signal. However, in order to encode the reverberation gain parameters corresponding to each sub-band of the channel signal, a relatively large number of bits need to be occupied. In some cases, when reverberation processing is performed on each sub-band of the channel signal, the auditory effect deteriorates.

Summary of the Invention

Means for Solving the Problems

[0006] The present application provides a multi-channel signal encoding method, a multi-channel signal decoding method, an encoder, and a decoder in order to improve the encoding efficiency.

[0007] According to a first aspect, a multi-channel signal encoding method is provided. The method includes steps of determining a downmix signal of a first channel signal and a second channel signal in a multi-channel signal, and reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal; determining target reverberation gain parameters that need to be encoded among the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal; generating parameter indication information, where the parameter indication information is used to indicate the sub-band corresponding to the target reverberation gain parameter; and encoding the target reverberation gain parameter, the parameter indication information, and the downmix signal to generate a bitstream.

[0008] In the present application, when the first channel signal and the second channel signal are encoded, the reverberation gain parameters corresponding to only some sub-bands of the first channel signal and the second channel signal may be encoded. Compared with the prior art method in which the reverberation gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal need to be encoded, the bit overhead can be reduced to some extent, and the encoding efficiency can be improved. Specifically, when the reverberation gain parameters corresponding to some sub-bands are encoded, a large number of saved bits can be used to encode another parameter or allocate more bits to the downmix signal, thereby improving the overall encoding performance.

[0009] Referring to the first aspect, in some implementations of the first aspect, the step of determining the target reverberation gain parameter that needs to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal includes determining the target reverberation gain parameter based on at least one of the energy of the first channel signal and the energy of the second channel signal, the inter-channel coherence IC between the first channel signal and the second channel signal, the energy of the downmix signal, and the inter-channel level difference ILD between the first channel signal and the second channel signal.

[0010] The coherence between the first channel signal and the second channel signal can be determined based on the energy of the channel signal or the energy of the downmix signal, IC, ILD, etc., and the target reverberation gain parameter to be encoded can be appropriately determined from the reverberation gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal based on the coherence between the first channel signal and the second channel signal. Therefore, bits can be saved to some extent considering the quality of the channel signal, and the encoding efficiency can be improved. Specifically, when the coherence between the first channel signal and the second channel signal is relatively low, only the reverberation gain parameters corresponding to the sub-bands in the low-frequency portion of the first channel signal and the second channel signal may be encoded. When the coherence between the first channel signal and the second channel signal is relatively high, in addition to the reverberation gain parameters corresponding to the sub-bands in the low-frequency portion of the first channel signal and the second channel signal, the reverberation gain parameters corresponding to the sub-bands in the high-frequency portion of the first channel signal and the second channel signal may also be encoded.

[0011] Referring to the first aspect, in some implementations of the first aspect, the step of determining the target reverberation gain parameter to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal includes the step of determining the target reverberation gain parameter based on at least one of the coherence between the energy of the first channel signal and the energy of the downmix signal, and the coherence between the energy of the second channel signal and the energy of the downmix signal.

[0012] The values of the energy of the first channel signal, the energy of the second channel signal, and the energy of the downmix signal may be values obtained after normalization processing.

[0013] The coherence between both the first channel signal and the second channel signal and the downmix signal can be conveniently measured using the energy of the channel signal, i.e., the target reverberation gain parameter that needs to be encoded can be conveniently determined by comparing the difference between the energy of the channel signal and the energy of the downmix signal. Specifically, when the difference between the energy of the channel signal and the energy of the downmix signal is relatively large, the coherence between the channel signal and the downmix signal may be considered to be relatively low. In this case, only the reverberation gain parameter corresponding to the subband of the low-frequency portion of the channel signal may be encoded.

[0014] Referring to the first aspect, in some implementations of the first aspect, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and based on at least one of the coherence between the energy of the first channel signal and the energy of the downmix signal and the coherence between the energy of the second channel signal and the energy of the downmix signal, the step of determining the target reverberation gain parameter includes: determining a first difference value between the energy of the first channel signal and the energy of the downmix signal, where the first difference value is used to indicate the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins; and when the first difference value is greater than a first threshold value, determining that the reverberation gain parameter corresponding to the subband of the first frequency band is the target reverberation gain parameter, where the first frequency band is a part of all the frequency bands of each of the first channel signal and the second channel signal.

[0015] Referring to the first aspect, in some implementations of the first aspect, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and based on at least one of the coherence between the energy of the first channel signal and the energy of the downmix signal and the coherence between the energy of the second channel signal and the energy of the downmix signal, the step of determining the target reverberation gain parameter includes determining a second difference value between the energy of the second channel signal and the energy of the downmix signal, where the second difference value is used to indicate the sum of the absolute values of the difference values between the energy of the second channel signal and the energy of the downmix signal in a plurality of frequency bins; and when the second difference value is greater than a second threshold value, determining that the reverberation gain parameter corresponding to the sub-band of the first frequency band is the target reverberation gain parameter, where the first frequency band is a part of all the frequency bands of each of the first channel signal and the second channel signal.

[0016] Referring to the first aspect, in some implementations of the first aspect, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and based on at least one of the coherence between the energy of the first channel signal and the energy of the downmix signal and the coherence between the energy of the second channel signal and the energy of the downmix signal, the step of determining the target reverberation gain parameter includes determining a first difference value between the energy of the first channel signal and the energy of the downmix signal, where the first difference value is used to indicate the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in a plurality of frequency bins; determining a second difference value between the energy of the second channel signal and the energy of the downmix signal, where the second difference value is used to indicate the sum of the absolute values of the difference values between the energy of the second channel signal and the energy of the downmix signal in a plurality of frequency bins; and when the first difference value is greater than a first threshold value and the second difference value is greater than a second threshold value, determining that the reverberation gain parameter corresponding to the sub-band of the first frequency band is the target reverberation gain parameter, where the first frequency band is a part of all the frequency bands of each of the first channel signal and the second channel signal.

[0017] The difference value between the energy of the first channel signal and the energy of the downmix signal in a plurality of frequency bins, and the difference value between the energy of the second channel signal and the energy of the downmix signal in a plurality of frequency bins may be values obtained after normalization processing.

[0018] When the coherence between the first channel signal or the second channel signal and the downmix signal is relatively high, the first channel signal and the second channel signal may be considered two channel signals that are relatively similar to each other (when two channel signals are relatively similar, the mixed signal obtained by mixing the two channel signals is relatively similar to the two channel signals before mixing). When the coherence between the first channel signal or the second channel signal and the downmix signal is relatively low, the first channel signal and the second channel signal may be considered two channel signals that are relatively different from each other.

[0019] The coherence between the first channel signal and the downmix signal is used as an example. By using a first difference value between the energy of the first channel signal and the energy of the downmix signal, the coherence between the first channel signal and the downmix signal may be measured. When the first difference value is relatively large, the coherence between the first channel signal and the downmix signal may be considered relatively low. When the first difference value is relatively small, the coherence between the first channel signal and the downmix signal may be considered relatively high.

[0020] The difference between the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal is the target Reverberation gain parameter To further determine, it can be conveniently determined by comparing the difference values between the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal in a plurality of frequency bins. Therefore, it is not necessary to compare the energy of the first channel signal and the energy of the second channel signal within all frequency bands.

[0021] When the energy of the first channel signal and / or the energy of the second channel signal is relatively different from the energy of the downmix signal, encoding the reverberation gain parameters corresponding to the sub-bands of some frequency bands of the first channel signal and the second channel signal can not only save some bits, but also improve the encoding performance. However, in the prior art, the reverberation gain parameters corresponding to the sub-bands of all frequency bands of the first channel signal and the second channel signal are encoded. In this case, since the difference between the first channel signal and the second channel signal is relatively large, if the reverberation gain parameters corresponding to the sub-bands of all frequency bands are still encoded, the reverberation processing is performed based on the reverberation gain parameters of all frequency bands, and the finally restored first channel signal and second channel signal have relatively large distortion compared with the original signals.

[0022] Referring to the first aspect, in some implementations of the first aspect, the frequency of the first frequency band is smaller than the frequency of another frequency band different from the first frequency band in the first channel signal and the second channel signal.

[0023] It should be understood that the first frequency band may be a low-frequency band.

[0024] When the difference between the first channel signal and the second channel signal is relatively large, the difference between the two channel signals is usually relatively large in the high-frequency part, but the difference between the two channel signals is relatively small in the low-frequency part. However, the channel signal in the low-frequency part has a greater impact on the human auditory experience. Therefore, when the difference between the first channel signal and the second channel signal is relatively large, only the reverberation gain parameters corresponding to the sub-bands of the low-frequency part may be encoded. In this way, not only can the encoded bits be saved, but also the auditory experience can be guaranteed.

[0025] Referring to the first aspect, in some implementations of the first aspect, the method is When the first difference value is less than or equal to the first threshold value and the second difference value is less than or equal to the second threshold value, determining, as target reverberation gain parameters, the reverberation gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal further includes.

[0026] Referring to the first aspect, in some implementations of the first aspect, when the first difference value is less than or equal to the first threshold value or the second difference value is less than or equal to the second threshold value, the reverberation gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal are determined as target reverberation gain parameters.

[0027] When the difference between both the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal is relatively large, in order to reduce the bit overhead during encoding and avoid signal distortion that occurs during reverberation processing as much as possible, only the reverberation gain parameters corresponding to some sub-bands may be encoded.

[0028] However, when the difference between both the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal is relatively small, the signal distortion caused by reverberation processing on the channel signal is very small. In order to obtain a better auditory effect, the reverberation gain parameters corresponding to all sub-bands may be encoded.

[0029] Referring to the first aspect, in some implementations of the first aspect, a plurality of frequency bins are within a second frequency band of each of the first channel signal and the second channel signal, and the frequencies of the second frequency band are greater than the frequencies of another frequency band different from the second frequency band in the first channel signal and the second channel signal.

[0030] The difference between both the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal can be conveniently determined by comparing the difference values between both the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal in a plurality of frequency bins in the high-frequency portion.

[0031] Referring to the first aspect, in some implementations of the first aspect, the step of determining a target reverberation gain parameter that needs to be encoded within the reverberation gain parameters corresponding to different subbands of the first channel signal and the second channel signal includes: determining the energy of N subbands of the downmix signal; determining M subbands from the N subbands, where the energy of any subband among the M subbands is greater than the energy of any subband among the N−M subbands within the N subbands excluding the M subbands, and both M and N are integers greater than 0 and M is less than N; and determining the target reverberation gain parameter based on the magnitude relationship between the energy of the M subbands and the energy of the N−M subbands.

[0032] It should be understood that when the downmix signal is a wideband signal, the N subbands may be all the subbands of the downmix signal, and when the downmix signal is an ultra-wideband signal, the N subbands may be the subbands of the downmix signal in the wideband portion.

[0033] The coherence between the first channel signal and the second channel signal can be determined based on the energy of different subbands of the downmix signal, and further, the target reverberation gain parameter that needs to be encoded is determined based on the coherence between the first channel signal and the second channel signal.

[0034] The downmix signal may be a wideband signal or an ultra-wideband signal. When the downmix signal is a wideband signal, the N sub-bands may be all the sub-bands of the downmix signal. When the downmix signal is an ultra-wideband signal, the N sub-bands may be the sub-bands of the downmix signal in the wideband portion.

[0035] In addition, alternatively, the M sub-bands may be determined based on the amplitude of each sub-band of the downmix signal, that is, the amplitude of any sub-band among the M sub-bands of the downmix signal is greater than the amplitude of any sub-band among the N - M sub-bands of the downmix signal. The value of M may be preset.

[0036] Referring to the first aspect, in some implementations of the first aspect, based on the magnitude relationship between the energy of the M sub-bands of the downmix signal and the energy of the N - M sub-bands of the downmix signal, the step of determining the target reverberation gain parameter includes the step of determining that the reverberation gain parameter corresponding to the sub-bands of the first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter when the average value of the energy of the M sub-bands is greater than K times the average value of the energy of the N - M sub-bands, where K is a real number greater than 0.

[0037] Referring to the first aspect, in some implementations of the first aspect, based on the magnitude relationship between the energy of the M sub-bands of the downmix signal and the energy of the N - M sub-bands of the downmix signal, the step of determining the target reverberation gain parameter includes the step of determining that the reverberation gain parameter corresponding to the sub-bands of the first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter when the sum of the energy of the M sub-bands is greater than L times the sum of the energy of the N - M sub-bands, where L is a real number greater than 0.

[0038] It should be understood that K and L may have different values.

[0039] For the downmix signal M The energy of M sub-bands and the energy of N - M sub-bands of the downmix signal may be compared by comparing the average value of the energy of the M sub-bands with the average value of the energy of the N - M sub-bands. To further reduce the computational complexity, the sum of the energy of the M sub-bands and the sum of the energy of the N - M sub-bands may be directly compared. In this way, the calculation process is simplified to some extent and the efficiency is improved.

[0040] When the difference between the energy of M sub-bands having relatively large energy and the energy of another sub-band having relatively small energy is relatively large, the difference between the first channel signal and the second channel signal may be considered relatively large. In this case, the reverberation gain parameters corresponding to the sub-bands in some frequency bands in the first channel signal and the second channel signal may be determined as the target reverberation gain parameters to be encoded. Specifically, the first frequency band may be a frequency band located in the low-frequency part of the first channel signal and the second channel signal.

[0041] Referring to the first aspect, in some implementations of the first aspect, the step of determining a target reverberation gain parameter to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal includes determining the energy of N sub-bands of the downmix signal, and determining M sub-bands from the N sub-bands, wherein the energy of any sub-band among the M sub-bands is greater than the energy of any sub-band among the N - M sub-bands within the N sub-bands excluding the M sub-bands; and when the index value of the first sub-band among the M sub-bands is smaller than a preset index value, determining that the reverberation gain parameter corresponding to the sub-bands of the first frequency band is the target reverberation gain parameter, wherein the frequency of any frequency bin within the first sub-band is greater than the frequency of any frequency bin within another sub-band among the M sub-bands excluding the first sub-band, and the first frequency band is part of all the frequency bands of each of the first channel signal and the second channel signal.

[0042] When the index value of the sub-band with the maximum frequency within the M sub-bands having relatively large energy is smaller than the preset index value, the energy distribution of the M sub-bands of the downmix signal is non-uniform, that is, the coherence between the first channel signal and the second channel signal may be considered relatively small. In this case, it may be necessary to encode only the reverberation gain parameters corresponding to the sub-bands of some frequency bands.

[0043] Referring to the first aspect, in some implementations of the first aspect, the step of determining a target reverberation gain parameter that needs to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal includes: determining the energy of N sub-bands of the downmix signal; determining J target sub-bands from the N sub-bands based on the energy of the N sub-bands, where the energy of any sub-band among the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, and both N and J are integers greater than 0 and J is less than N; and determining the reverberation gain parameters corresponding to the J target sub-bands as the target reverberation gain parameters.

[0044] Based on the energy of each sub-band of the downmix signal, a predetermined number of sub-bands are directly selected from all sub-bands, and the reverberation gain parameters corresponding to the predetermined number of sub-bands are determined as the target reverberation gain parameters. As a result, the reverberation gain parameters that need to be encoded can be selected more flexibly.

[0045] Referring to the first aspect, in some implementations of the first aspect, the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

[0046] The energy of the downmix signal is estimated or inferred based on the energy of the first channel signal and the energy of the second channel signal, and the computational complexity can be reduced to a certain extent.

[0047] According to a second aspect, a multi-channel signal decoding method is provided. The method includes receiving a bitstream, and based on the bitstream, obtaining a downmix signal of a first channel signal and a second channel signal in the multi-channel signal, and parameter indication information, where the parameter indication information is used to indicate an encoded target reverberation gain parameter in a reverberation gain parameter corresponding to different sub-bands of the first channel signal and the second channel signal; obtaining the target reverberation gain parameter from the bitstream according to the parameter indication information; and determining the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameter.

[0048] In the present application, the target reverberation gain parameter encoded by the encoder can be determined using the parameter indication information, and then, based on the target reverberation gain parameter, reverberation processing is performed on corresponding sub-bands of the first channel signal and the second channel signal.

[0049] According to a third aspect, a multi-channel signal encoding method is provided. The method includes determining a downmix signal of a first channel signal and a second channel signal in the multi-channel signal, and a reverberation gain parameter corresponding to different sub-bands of the first channel signal and the second channel signal; determining a target reverberation gain parameter that needs to be encoded in the reverberation gain parameter corresponding to different sub-bands of the first channel signal and the second channel signal based on the energy of N sub-bands of the downmix signal, where N is an integer greater than 0; and encoding the downmix signal and the target reverberation gain parameter.

[0050] In the present application, based on the energy of each sub-band of the downmix signal, a specific number of sub-bands are directly selected from all the sub-bands, and as a result, the reverberation gain parameters that need to be encoded can be selected more flexibly. In addition, compared with the method of determining the reverberation gain parameter corresponding to the sub-band of the fixed frequency band as the target reverberation gain parameter, the reverberation gain parameters corresponding to several sub-bands that may not be adjacent in the frequency domain can be directly selected as the target reverberation gain parameters.

[0051] Referring to the third aspect, in some implementations of the third aspect, the step of determining the target reverberation gain parameter to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal based on the energy of N sub-bands of the downmix signal includes: determining J target sub-bands from the N sub-bands based on the energy of the N sub-bands, where the energy of any sub-band among the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, both N and J are integers greater than 0, and J is less than N; and determining the reverberation gain parameters corresponding to the J target sub-bands as the target reverberation gain parameters.

[0052] In the present application, based on the energy of each sub-band of the downmix signal, a predetermined number of sub-bands are directly selected from all the sub-bands, and the reverberation gain parameters corresponding to the predetermined number of sub-bands are determined as the target reverberation gain parameters, and as a result, the reverberation gain parameters that need to be encoded can be selected more flexibly.

[0053] According to a fourth aspect, a multi-channel signal decoding method is provided. The method includes receiving a bitstream; determining, based on the bitstream, downmix signals of a first channel signal and a second channel signal in a multi-channel signal; determining, based on the energy of N sub-bands of the downmix signals, encoded target reverberation gain parameters in reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal, where N is an integer greater than 0; determining target reverberation gain parameters based on the bitstream; and determining the first channel signal and the second channel signal based on the downmix signals and the target reverberation gain parameters.

[0054] In the present application, on the decoder side, based on the energy of a plurality of sub-bands of the downmix signals, the encoded target reverberation gain parameters in the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal can be directly determined. As a result, the bits occupied by the decoder side for transmitting indication information indicating the encoded target reverberation gain parameters are reduced, and the signaling overhead can be reduced to a certain extent.

[0055] Referring to the fourth aspect, in some implementations of the fourth aspect, based on the energies of the N subbands of the downmix signal, the step of determining the encoded target reverberation gain parameters in the reverberation gain parameters corresponding to different subbands of the first channel signal and the second channel signal is the step of determining J target subbands from the N subbands based on the energies of the N subbands, wherein the energy of any subband among the J target subbands is greater than the energy of another subband different from the J target subbands, both N and J are integers greater than 0, and J is less than N, and the step of determining the reverberation gain parameters corresponding to the J target subbands as the target reverberation gain parameters.

[0056] According to a fifth aspect, an encoder is provided, and the encoder includes a module or unit configured to execute the method in the first aspect or various implementations of the first aspect.

[0057] According to a sixth aspect, a decoder is provided, Decoder and includes a module or unit configured to execute the method in the second aspect or various implementations of the second aspect.

[0058] According to a seventh aspect, an encoder is provided, and the encoder includes a module or unit configured to execute the method in the third aspect or various implementations of the third aspect.

[0059] According to an eighth aspect, a decoder is provided, Decoder and includes a module or unit configured to execute the method in the fourth aspect or various implementations of the fourth aspect.

[0060] According to a ninth aspect, an encoder including a memory and a processor is provided, the memory is configured to store a program, the processor is configured to execute the program, and when the program is executed, the processor executes the method in the first aspect or various implementations of the first aspect.

[0061] According to a tenth aspect, a decoder including a memory and a processor is provided, the memory is configured to store a program, the processor is configured to execute the program, and when the program is executed, the processor executes the method in the second aspect or various implementations of the second aspect.

[0062] According to an eleventh aspect, an encoder including a memory and a processor is provided, the memory is configured to store a program, the processor is configured to execute the program, and when the program is executed, the processor executes the method in the third aspect or various implementations of the third aspect.

[0063] According to a twelfth aspect, a decoder including a memory and a processor is provided, the memory is configured to store a program, the processor is configured to execute the program, and when the program is executed, the processor executes the method in the fourth aspect or various implementations of the fourth aspect.

[0064] According to a thirteenth aspect, a computer-readable medium is provided, the computer-readable medium stores program code to be executed by a device, and the program code includes instructions used to execute the method in the first aspect or various implementations of the first aspect.

[0065] According to a fourteenth aspect, a computer-readable medium is provided, the computer-readable medium stores program code to be executed by a device, and the program code includes instructions used to execute the method in the second aspect or various implementations of the second aspect.

[0066] According to a 15th aspect, a computer-readable medium is provided, the computer-readable medium stores program code to be executed by a device, and the program code includes instructions used to execute the method in the 3rd aspect or various implementation forms of the 3rd aspect.

[0067] According to a 16th aspect, a computer-readable medium is provided, the computer-readable medium stores program code to be executed by a device, and the program code includes instructions used to execute the method in the 4th aspect or various implementation forms of the 4th aspect.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0069] Hereinafter, the technical solutions of the present application will be described with reference to the accompanying drawings. In order to better understand the multi-channel signal encoding method and the multi-channel signal decoding method in the embodiments of the present application, hereinafter, first, with reference to FIGS. 1 and 2, the multi-channel signal encoding method and the multi-channel signal decoding method in the prior art will be briefly described.

[0070] FIG. 1 shows a process of encoding a left channel signal and a right channel signal in the prior art. The encoding process shown in FIG. 1 specifically includes the following steps.

[0071] 110. Perform spatial parameter analysis and downmixing processing on the left channel signal (represented by L in the figure) and the right channel signal (represented by R in the figure).

[0072] Specifically, step 110 specifically includes performing spatial parameter analysis on the left channel signal and the right channel signal to obtain the spatial parameters of the left channel signal and the spatial parameters of the right channel signal, and performing downmixing processing on the left channel signal and the right channel signal to obtain a downmix signal (the downmix signal obtained after the downmixing processing is a monaural audio signal, and the original two channels of the audio signal are combined into one channel of the audio signal by the downmixing processing).

[0073] (Sometimes called spatial detection parameters) The spatial parameters include inter-channel coherence (IC), inter-channel level difference (ILD), inter-channel time difference (ITD), inter-channel phase difference (IPD), and the like.

[0074] IC describes the cross-coherence or coherence between channels. This parameter can determine the detection of the sound field range and improve the spatial detection and sound stability of the audio signal. ILD is used to distinguish the horizontal angle of the stereo source and describe the intensity difference between channels. This parameter affects the frequency components of the entire spectrum. ITD and IPD are spatial parameters representing the horizontal direction of the sound source and describe the time difference and phase difference between channels. These parameters mainly affect the frequency components below 2 kHz. In the case of a two-channel signal, ITD can represent the time delay between the left channel signal and the right channel signal of the stereo, and IPD can represent the waveform similarity between the left channel signal and the right channel signal of the stereo after time alignment. ILD, ITD, and IPD can determine the detection of the sound source position by the human ear, effectively determine the sound source position, and play an important role in the restoration of stereo signals.

[0075] 120. Encode the downmix signal to obtain a bitstream.

[0076] 130. Encode the spatial parameters to obtain a bitstream.

[0077] 140. Multiplex the bitstream obtained by encoding the downmix signal and the bitstream obtained by encoding the spatial parameters to obtain a bitstream.

[0078] The bitstream obtained by encoding may be stored or transmitted to a decoder-side device.

[0079] Figure 2 shows a process of decoding a left channel signal and a right channel signal in the prior art. The decoding process shown in Figure 2 specifically includes the following steps.

[0080] 210. Demultiplex the bitstream to separately obtain the bitstream obtained by encoding the downmix signal and the bitstream obtained by encoding the spatial parameters.

[0081] Based on the demultiplexed bitstream, the downmix signal and the spatial parameters are obtained by decoding.

[0082] In step 210, the decoder side can separately decode the downmix signal and the spatial parameters.

[0083] The spatial parameters are used to indicate the ICs of the left channel signal and the right channel signal.

[0084] 220. Obtain a decoherence signal.

[0085] Furthermore, the left-channel signal and the right-channel signal are obtained based on the decoded downmix signal and the decoherence signal of the current frame.

[0086] Based on the spatial parameters, the left-channel signal, and the right-channel signal, obtain the finally output left-channel signal and right-channel signal (represented by L’ and R’ in FIG. 2, respectively).

[0087] It should be understood that the left-channel signal and the right-channel signal in step 230 (represented by L’ and R’ in FIG. 2, respectively) are obtained by decoding and may be distorted to some extent compared with the left-channel signal and the right-channel signal encoded on the encoder side.

[0088] Specifically, the downmix signal may be filtered, and then the inter-channel coherence parameter is used to modify the filtered downmix signal to obtain the decoherence signal.

[0089] The purpose of generating the decoherence signal is to improve the reverberation feeling of the stereo signal finally generated on the decoder side, widen the sound field width of the stereo signal, so that the output audio signal becomes mellower and fuller from the perspective of hearing. The reverberation feeling is essentially the effect of delay such as reflecting and refracting the original audio signal differently, and then superimposing the reflected and refracted audio signals on the original audio signal and entering the human ear.

[0090] In the prior art, when a multi-channel signal is encoded, the multi-channel signal is usually divided into a plurality of sub-bands, an IC corresponding to each sub-band is determined, and the IC corresponding to each sub-band is then encoded. However, when encoding the IC corresponding to each sub-band, the number of bits occupied during encoding definitely increases. In some cases, for example, when the coherence between a plurality of channel signals is relatively low, the high-frequency portions of the plurality of channel signals are relatively different. In this case, the ICs corresponding to the high-frequency portions of the plurality of channel signals are still encoded, and when the decoder side performs reverberation processing on the high-frequency portions of the plurality of channel signals based on the ICs corresponding to the high-frequency portions of the plurality of channel signals, the plurality of restored channel signals are greatly distorted.

[0091] Therefore, one embodiment of the present application provides a multi-channel signal encoding method so that the reverberation gain parameters of some sub-bands in the multi-channel signal can be adaptively selected for encoding in order to effectively use bits. Hereinafter, with reference to the accompanying drawings, the multi-channel signal encoding method in this embodiment of the present application will be described in detail.

[0092] FIG. 3 is a schematic flowchart of a multi-channel signal encoding method according to an embodiment of the present application. The method of FIG. 3 may be executed by an encoder-side device or an encoder. The method of FIG. 3 includes the following steps.

[0093] 310. Determine the downmix signals of the first channel signal and the second channel signal in the multi-channel signal, and the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal.

[0094] The multi-channel signal may be a plurality of channel signals. In addition, before step 310, the method may include the step of obtaining the first channel signal and the second channel signal in the multi-channel signal.

[0095] This embodiment of the present application does not set a limit on the order between the process of determining the downmix signal and the process of determining the reverberation gain parameters corresponding to different subbands of the first channel signal and the second channel signal. The processes may be executed simultaneously or in order.

[0096] Specifically, the downmix signal may be obtained by performing a downmixing process on the first channel signal and the second channel signal. The spatial parameters of the first channel signal and the second channel signal are obtained by performing a spatial parameter analysis on the first channel signal and the second channel signal. The spatial parameters include reverberation gain parameters corresponding to different subbands of the first channel signal and the second channel signal, as well as other spatial parameters such as IC, ILD, ITD, and IPD.

[0097] It should be understood that the first channel signal and the second channel signal correspond to the same spatial parameters, specifically, the first channel signal and the second channel signal also correspond to the same initial reverberation gain parameters. That is, the spatial parameters of the first channel signal and the second channel signal are the same, and the initial reverberation gain parameters of the first channel signal and the second channel signal are the same.

[0098] Furthermore, assuming that each of the first channel signal and the second channel signal includes 10 subbands and each subband corresponds to one reverberation gain parameter, the reverberation gain parameters corresponding to the subbands with the same index value of the first channel signal and the second channel signal are the same.

[0099] In addition, the first channel signal, the second channel signal, and the downmix signal may be channel signals obtained after normalization processing.

[0100] 320. Determine the target reverberation gain parameter that needs to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal.

[0101] 330. Generate parameter indication information, which is used to indicate the sub-bands corresponding to the target reverberation gain parameter.

[0102] The parameter indication information can indicate the sub-bands corresponding to the target reverberation gain parameter by using flag bits. For example, each of the first channel signal and the second channel signal includes 10 sub-bands (the index numbers of the sub-bands are 0 to 9), the parameter indication information includes 10 flag bits, and the 10 flag bits correspond continuously to the 10 sub-bands of each of the first channel signal and the second channel signal. When the flag bit corresponding to a sub-band is 1, the reverberation gain parameter corresponding to the sub-band is the target reverberation gain parameter that needs to be encoded. However, when the flag bit corresponding to a sub-band is 0, the reverberation gain parameter corresponding to the sub-band is not the target reverberation gain parameter. In this way, when performing encoding, the encoder side encodes only the reverberation gain parameters corresponding to the sub-bands where the flag bits are 1.

[0103] Alternatively, the parameter display information may only include one flag bit, and the flag bit is 1 or 0. When the flag bit is 1, it indicates that the reverberation gain parameter of the selected target sub-band should be encoded. When the flag bit is 0, it indicates that the reverberation gain parameters of all sub-bands should be encoded.

[0104] Specifically, the index numbers of all sub-bands of the first channel signal and the second channel signal are from 0 to 9, and the sub-bands with index numbers from 0 to 5 are target sub-bands. In this case, when the flag bit of the parameter indication information is 1, the reverberation gain parameters of the sub-bands with index numbers from 0 to 5 should be encoded. When the flag bit of the parameter indication information is 0, the reverberation gain parameters of the sub-bands with index numbers from 0 to 9 should be encoded.

[0105] 340. To generate a bitstream, encode the target reverberation gain parameter, the parameter indication information, and the downmix signal.

[0106] In the present application, when the first channel signal and the second channel signal are encoded, the reverberation gain parameters corresponding to only some sub-bands of the first channel signal and the second channel signal may be encoded. Compared with the prior art method in which the reverberation gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal need to be encoded, the bit overhead can be reduced to a certain extent, and the encoding efficiency can be improved.

[0107] Specifically, when the reverberation gain parameters corresponding to some sub-bands are encoded, a large number of saved bits can be used to encode another parameter or allocate more bits to the downmix signal, thereby improving the overall encoding performance.

[0108] For example, the reverberation gain parameters corresponding to the sub-bands in the low-frequency part of the first channel signal and the second channel signal may be selected as the target reverberation gain parameters to be encoded, and the reverberation gain parameters corresponding to the sub-bands in the high-frequency part of the first channel signal and the second channel signal should not be encoded.

[0109] In some cases, when reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal are generated, reverberation gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal may be generated. That is, all reverberation gain parameters of the first channel signal and the second channel signal are generated, and then only the target reverberation gain parameters within all the reverberation gain parameters are encoded during encoding.

[0110] Alternatively, in order to further improve the encoding efficiency, when a spatial parameter analysis is performed on the first channel signal and the second channel signal, only the target reverberation gain parameters may be generated, and the remaining reverberation gain parameters that should not be encoded are not generated. Specifically, when the target reverberation gain parameters correspond to the target sub-bands of the first channel signal and the second channel signal, when a spatial parameter analysis is performed on the first channel signal and the second channel signal, only the reverberation gain parameters corresponding to the target sub-bands of the first channel signal and the second channel signal may be determined, and there is no need to determine the reverberation gain parameters corresponding to other sub-bands of the first channel signal and the second channel signal. In this way, the encoding efficiency can be further improved.

[0111] In some cases, in one embodiment, the step of determining the target reverberation gain parameters that need to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal includes determining the target reverberation gain parameters based on at least one of the energy of the first channel signal and the energy of the second channel signal, the IC between the first channel signal and the second channel signal, the magnitude of the energy of different sub-bands of the downmix signal, and the ILD between the first channel signal and the second channel signal.

[0112] Specifically, the coherence between the first channel signal and the second channel signal can be determined based on the energy of the first channel signal and the energy of the second channel signal or the energy of the downmix signal, the inter-channel coherence between the first channel signal and the second channel signal, and the inter-channel level difference between the first channel signal and the second channel signal. In addition, the target reverberation gain parameter to be encoded can be appropriately determined based on the coherence between the first channel signal and the second channel signal from the reverberation gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal, and as a result, bits can be saved to some extent and the encoding efficiency can be improved.

[0113] For example, when the coherence between the first channel signal and the second channel signal is relatively low, only the reverberation gain parameters corresponding to the sub-bands in the low-frequency part of the first channel signal and the second channel signal may be encoded. When the coherence between the first channel signal and the second channel signal is relatively high, in addition to the reverberation gain parameters corresponding to the sub-bands in the low-frequency part of the first channel signal and the second channel signal, the reverberation gain parameters corresponding to the sub-bands in the high-frequency part of the first channel signal and the second channel signal may also be encoded. That is, when the coherence between the first channel signal and the second channel signal is relatively high, the reverberation gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal may be encoded.

[0114] When a target reverberation gain parameter is determined based on the IC between the first channel signal and the second channel signal, the size of the IC value between the first channel signal and the second channel signal may be determined, and the coherence between the first channel signal and the second channel signal may be determined based on the size of the IC value. For example, when the IC value between the first channel signal and the second channel signal is relatively small (in this case, the coherence between the first channel signal and the second channel signal may be considered relatively low), the reverberation gain parameter corresponding to the sub-band of the low-frequency portion of the first channel signal and the second channel signal may be determined as the target reverberation gain parameter. When the IC value between the first channel signal and the second channel signal is relatively large (in this case, the coherence between the first channel signal and the second channel signal may be considered relatively high), the reverberation gain parameter corresponding to the sub-band of the low-frequency portion and the sub-band of the high-frequency portion of the first channel signal and the second channel signal (that is, the sub-bands of all frequency bands of the first channel signal and the second channel signal) may be determined as the target reverberation gain parameter.

[0115] In some cases, in one embodiment, the step of determining the target reverberation gain parameter that needs to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal includes the step of determining the target reverberation gain parameter based on at least one of the coherence between the energy of the first channel signal and the energy of the downmix signal and the coherence between the energy of the second channel signal and the energy of the downmix signal.

[0116] That is, when the target reverberation gain parameter is determined, the target reverberation gain parameter may be determined separately based on the coherence between the energy of the first channel signal and the energy of the downmix signal, or the coherence between the energy of the second channel signal and the energy of the downmix signal, or the target reverberation gain parameter may be determined together based on the coherence between the energy of the first channel signal and the energy of the downmix signal and the coherence between the energy of the second channel signal and the energy of the downmix signal.

[0117] Specifically, in some embodiments, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and based on at least one of the coherence between the energy of the first channel signal and the energy of the downmix signal and the coherence between the energy of the second channel signal and the energy of the downmix signal, the step of determining the target reverberation gain parameter includes a step of determining a first difference value between the energy of the first channel signal and the energy of the downmix signal, where the first difference value is used to indicate the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in a plurality of frequency bins, and a step of determining that the reverberation gain parameter corresponding to the sub-band of the first frequency band is the target reverberation gain parameter when the first difference value is greater than a first threshold value, where the first frequency band is a part of all the frequency bands of each of the first channel signal and the second channel signal.

[0118] In other embodiments, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and the step of determining the target reverberation gain parameter based on at least one of the coherence between the energy of the first channel signal and the energy of the downmix signal and the coherence between the energy of the second channel signal and the energy of the downmix signal includes: determining a second difference value between the energy of the second channel signal and the energy of the downmix signal, where the second difference value is used to indicate the sum of the absolute values of the difference values between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins; and when the second difference value is greater than a second threshold value, determining that the reverberation gain parameter corresponding to the sub-band of the first frequency band is the target reverberation gain parameter, where the first frequency band is part of all the frequency bands of each of the first channel signal and the second channel signal.

[0119] In other embodiments, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and based on at least one of the coherence between the energy of the first channel signal and the energy of the downmix signal and the coherence between the energy of the second channel signal and the energy of the downmix signal, the step of determining the target reverberation gain parameter includes: determining a first difference value between the energy of the first channel signal and the energy of the downmix signal, where the first difference value is used to represent the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in a plurality of frequency bins; determining a second difference value between the energy of the second channel signal and the energy of the downmix signal, where the second difference value is used to represent the sum of the absolute values of the difference values between the energy of the second channel signal and the energy of the downmix signal in a plurality of frequency bins; and when the first difference value is greater than a first threshold value and the second difference value is greater than a second threshold value, determining that the reverberation gain parameter corresponding to the sub-band of the first frequency band is the target reverberation gain parameter, where the first frequency band is a part of all the frequency bands of each of the first channel signal and the second channel signal.

[0120] The difference value between the energy of the first channel signal and the energy of the downmix signal in a plurality of frequency bins and the difference value between the energy of the second channel signal and the energy of the downmix signal in a plurality of frequency bins may be values obtained after normalization processing.

[0121] The first threshold value and the second threshold value may be preset. In addition, the first threshold value and the second threshold value may be the same or different.

[0122] The coherence between both the first channel signal and the second channel signal and the downmix signal can be conveniently measured based on the energy of the channel signal, that is, the target reverberation gain parameter to be encoded can be conveniently determined by comparing the difference between the energy of the channel signal and the energy of the downmix signal.

[0123] For example, when the difference between the energy of the first channel signal and the energy of the downmix signal is relatively large, the coherence between the first channel signal and the downmix signal may be considered to be relatively low. In this case, only the reverberation gain parameter corresponding to the subband of the low-frequency part of the first channel signal may be encoded.

[0124] When the coherence between the first channel signal or the second channel signal and the downmix signal is relatively high, the first channel signal and the second channel signal may be considered to be two channel signals that are relatively similar to each other (when two channel signals are relatively similar, the mixed signal obtained by mixing the two channel signals is relatively similar to the two channel signals before mixing). When the coherence between the first channel signal or the second channel signal and the downmix signal is relatively low, the first channel signal and the second channel signal may be considered to be two channel signals that are relatively different from each other.

[0125] The coherence between the first channel signal and the downmix signal is used as an example. By using a first difference value between the energy of the first channel signal and the energy of the downmix signal, the coherence between the first channel signal and the downmix signal may be measured. When the first difference value is relatively large, the coherence between the first channel signal and the downmix signal may be considered to be relatively low. When the first difference value is relatively small, the coherence between the first channel signal and the downmix signal may be considered to be relatively high.

[0126] When at least one of the first difference value and the second difference value exceeds the corresponding threshold value, the coherence between the first channel signal and the second channel signal may be considered to be relatively low. In this case, reverberation gain parameters corresponding to sub-bands in some frequency bands of the first channel signal and the second channel signal are encoded, thereby not only saving bits to some extent but also improving the encoding performance. However, in this case, in the prior art, the reverberation gain parameters corresponding to sub-bands in all frequency bands of the first channel signal and the second channel signal are still encoded. In this case, since the difference between the first channel signal and the second channel signal is relatively large, when the reverberation gain parameters corresponding to sub-bands in all frequency bands are still encoded, the reverberation processing is performed based on the reverberation gain parameters in all frequency bands, and the finally restored first channel signal and second channel signal have relatively large distortion compared to the original signals.

[0127] Certainly, alternatively, the reverberation gain parameters corresponding to the sub-bands in the first frequency band of the first channel signal and the second channel signal can be determined as the target reverberation gain parameters only when both the first difference value and the second difference value are greater than the corresponding threshold value.

[0128] The frequency of the first frequency band may be lower than the frequency of another frequency band different from the first frequency band in the first channel signal and the second channel signal. Specifically, the first frequency band may be the frequency band having the lowest frequency in the first channel signal and the second channel signal. That is, the reverberation gain parameters corresponding to the sub-bands in the lowest frequency band in the first channel signal and the second channel signal may be determined as the target reverberation gain parameters.

[0129] Alternatively, the first frequency band may be the frequency band of the intermediate frequency values in the first channel signal and the second channel signal (some frequencies in all the frequency bands of the first channel signal and the second channel signal are greater than the frequencies of the first frequency band, and the frequencies of another part of all the frequency bands are smaller than the frequencies of the first frequency band), that is, the reverberation gain parameter corresponding to the sub-band of the intermediate frequency values of the first channel signal and the second channel signal may be determined as the target reverberation gain parameter.

[0130] In some cases, a plurality of frequency bins are within the second frequency band of each of the first channel signal and the second channel signal, and the frequencies of the second frequency band are greater than the frequencies of another frequency band different from the second frequency band in the first channel signal and the second channel signal.

[0131] That is, a plurality of frequency bins are located within the second frequency band having relatively high frequencies. Therefore, the difference value between both the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal can be conveniently determined by comparing the difference between both the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal in a plurality of frequency bins in the high-frequency part. Therefore, it is not necessary to compare the difference between both the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal over the entire frequency band, thereby simplifying the calculation process.

[0132] The difference value between both the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal can be conveniently determined by comparing the differences between both the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal in a plurality of frequency bins. Further, the target reverberation gain parameter is determined based on the difference value between both the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal, and it is not necessary to compare the differences between both the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal in all frequency bands.

[0133] In some cases, in one embodiment, the method of FIG. 3 further includes determining, as the target reverberation gain parameter, the reverberation gain parameters corresponding to all subbands of the first channel signal and the second channel signal when the first difference value is less than or equal to the first threshold value and the second difference value is less than or equal to the second threshold value.

[0134] When the first difference value is less than or equal to the first threshold value and the second difference value is less than or equal to the second threshold value, the difference between both the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal is relatively small. In this case, the coherence between the first channel signal and the second channel signal may be considered to be relatively large. To improve the reverberation feeling of the output channel signal, the reverberation gain parameters corresponding to all subbands may be encoded.

[0135] When the difference between both the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal is relatively large, only the reverberation gain parameters corresponding to some subbands may be encoded in order to reduce the bit overhead during encoding and avoid the signal distortion that occurs during reverberation processing as much as possible. When the difference between both the energy of the first channel signal and the energy of the second channel signal and the energy of the downmix signal is relatively small, the signal distortion caused by the reverberation processing for the channel signal is very small. In order to obtain a better auditory effect, the reverberation gain parameters corresponding to all subbands may be encoded.

[0136] Specifically, when the first channel signal is a left channel signal and the second channel signal is a right channel signal, the first difference value and the second difference value may be calculated based on the following formula.

Number

Number

[0137] diff_l_h is the first difference value, diff_r_h is the second difference value, each frequency band of the left channel signal and the right channel signal includes a high-frequency part and a low-frequency part, M1 is the start frequency bin of the high-frequency part, M2 is the end frequency bin of the high-frequency part, mag_l[k] is the energy or amplitude value of the left channel signal at the frequency bin with index k between M1 and M2, mag_r[k] is the energy or amplitude value of the right channel signal at the frequency bin with index k between M1 and M2, mag_dmx[k] is the energy or amplitude value of the downmix signal at the frequency bin with index k between M1 and M2, and mag_dmx[k] may be calculated using the downmix signal itself or may be calculated based on the energy or amplitude values of the left channel signal and the right channel signal.

[0138] After the first difference value and the second difference value are calculated based on formulas (1) and (2), an inter-frame smoothing process may be further performed on the first difference value and the second difference value (the smoothing process may be performed on the first difference value, the second difference value, and the difference value calculated in the previous frame). Then, by using the relationship between both the first difference value and the second difference value obtained by the smoothing process and a preset threshold value, a target reverberation gain parameter is determined.

[0139] In some cases, in one embodiment, the step of determining a target reverberation gain parameter that needs to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal includes: determining the energy of N sub-bands of the downmix signal; determining M sub-bands from the N sub-bands, where the energy of any sub-band among the M sub-bands is greater than the energy of any sub-band among the N - M sub-bands excluding the M sub-bands, and both M and N are integers greater than 0 and M is less than N; and determining the target reverberation gain parameter based on the magnitude relationship between the energy of the M sub-bands and the energy of the N - M sub-bands.

[0140] The coherence between the first channel signal and the second channel signal can be determined based on the energy of different sub-bands of the downmix signal. Further, the target reverberation gain parameter that needs to be encoded is determined based on the coherence between the first channel signal and the second channel signal.

[0141] Specifically, the step of determining the target reverberation gain parameter based on the magnitude relationship between the energies of the M sub-bands of the downmix signal and the energies of the N-M sub-bands of the downmix signal includes the step of determining that the reverberation gain parameter corresponding to the sub-bands in the first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter when the sum of the energies of the M sub-bands is greater than K times the sum of the energies of the N-M sub-bands, where K is a real number greater than 0.

[0142] The step of determining the target reverberation gain parameter based on the magnitude relationship between the energies of the M sub-bands of the downmix signal and the energies of the N-M sub-bands of the downmix signal includes the step of determining that the reverberation gain parameter corresponding to the sub-bands in the first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter when the average value of the energies of the M sub-bands is greater than L times the average value of the energies of the N-M sub-bands, where L is a real number greater than 0.

[0143] It should be understood that K and L may have different values. More specifically, when M is greater than N-M, K may be smaller than L, and when M is smaller than N-M, K may be larger than L.

[0144] The energies of the N sub-bands of the downmix signal and the energies of the N-M sub-bands of the downmix signal may be compared by comparing the average value of the energies of the M sub-bands of the downmix signal with the average value of the energies of the N-M sub-bands of the downmix signal. To further reduce the computational complexity, the sum of the energies of the M sub-bands of the downmix signal and the sum of the energies of the N-M sub-bands of the downmix signal may be directly compared. In this way, the calculation process is simplified to a certain extent and the efficiency is improved.

[0145] When the difference between the energy of M sub-bands having relatively large energy of the downmix signal and the energy of another sub-band having relatively small energy is relatively large, the difference between the first channel signal and the second channel signal may be considered relatively large. In this case, the reverberation gain parameters corresponding to the sub-bands of some frequency bands in the first channel signal and the second channel signal may be determined as target reverberation gain parameters to be encoded. Specifically, the first frequency band may be a frequency band in the low frequency portion of the first channel signal and the second channel signal, or may be a frequency band in the intermediate frequency portion of the first channel signal and the second channel signal.

[0146] In some cases, in one embodiment, the step of determining the target reverberation gain parameter to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal includes determining the energy of N sub-bands of the downmix signal, and determining M sub-bands from the N sub-bands, wherein the energy of any sub-band in the M sub-bands is greater than the energy of any sub-band in the N - M sub-bands among the N sub-bands excluding the M sub-bands, and when the index value of the first sub-band in the M sub-bands is smaller than a preset index value, determining that the reverberation gain parameter corresponding to the sub-band of the first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter, wherein the frequency of any frequency bin of the first sub-band is greater than the frequency of any frequency bin of another sub-band among the M sub-bands excluding the first sub-band, and the first frequency band is part of all frequency bands of each of the first channel signal and the second channel signal.

[0147] When the index value of the sub-band with the maximum frequency in M sub-bands having a relatively large energy is smaller than the preset index value, the energy distribution of the M sub-bands of the downmix signal is non-uniform, that is, the coherence between the first channel signal and the second channel signal may be considered relatively small. In this case, only the reverberation gain parameters corresponding to the sub-bands in some frequency bands need to be encoded.

[0148] The downmix signal may be a wideband signal or an ultra-wideband signal. When the downmix signal is a wideband signal, the N sub-bands may be all the sub-bands of the downmix signal, and when the downmix signal is an ultra-wideband signal, the N sub-bands may be the sub-bands of the downmix signal in the wideband portion.

[0149] The M sub-bands may be determined from the N sub-bands based on the amplitude of each sub-band of the downmix signal in addition to the magnitude of the energy of each sub-band of the downmix signal. Specifically, the M sub-bands may be determined based on the amplitude of each sub-band of the downmix signal such that the amplitude of any sub-band among the M sub-bands is greater than the amplitude of any sub-band among the N - M sub-bands.

[0150] The value of M may be a preset value before encoding. For example, the downmix signal includes a total of 10 sub-bands. In this case, 4 sub-bands having the maximum energy or amplitude may be selected. When the energy or amplitude value (which may be the sum of the energy or amplitude values or the average value of the energy or amplitude values) of the 4 sub-bands of the downmix signal is greater than a predetermined multiple of the energy or amplitude value of the remaining 6 sub-bands of the downmix signal, the reverberation gain parameter corresponding to the first frequency band of the first channel signal and the second channel signal is determined to be the target reverberation gain parameter.

[0151] In this embodiment of the present application, it should be understood that the target reverberation gain parameter may be determined based on at least one of the following conditions. When at least one of the following conditions is valid, some reverberation gain parameters may be determined as the target reverberation gain parameter.

[0152] Condition 1: One or more difference values between the energy of the first channel signal and / or the energy of the second channel signal and the energy of the downmix signal are greater than one or more preset thresholds.

[0153] Condition 2: The energy of the M subbands of the downmix signal is greater than a predetermined multiple of the energy of the N - M subbands of the downmix signal.

[0154] Condition 3: The index value of the first subband among the M subbands is greater than the preset index value.

[0155] The frequency of any spectral coefficient in the first subband is greater than the frequency of any spectral coefficient in another subband among the M subbands excluding the first subband.

[0156] In some cases, in one embodiment, the step of determining a target reverberation gain parameter to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal includes determining the energy of N sub-bands of the downmix signal, and determining J target sub-bands from the N sub-bands based on the energy of the N sub-bands, where the energy of any sub-band among the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, and both N and J are integers greater than 0 and J is less than N, and determining the reverberation gain parameters corresponding to the J target sub-bands as the target reverberation gain parameters. J may be a preset predetermined number.

[0157] Based on the energy of each sub-band of the downmix signal, a predetermined number of sub-bands are directly selected from all the sub-bands, and the reverberation gain parameters corresponding to the predetermined number of sub-bands are determined as the target reverberation gain parameters, so that the reverberation gain parameters that need to be encoded can be selected more flexibly.

[0158] Compared with the method of determining the reverberation gain parameters corresponding to the sub-bands in the fixed frequency band as the target reverberation gain parameters, the reverberation gain parameters corresponding to some sub-bands that may not be adjacent in the frequency domain can be directly and flexibly selected as the target reverberation gain parameters.

[0159] In some cases, in one embodiment, the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal. The energy of the downmix signal may be calculated based on the downmix signal itself, or may be estimated or inferred using the energy of the first channel signal and the energy of the second channel signal. When the energy of the downmix signal is determined using the energy of the first channel signal and the energy of the second channel signal, the calculation process can be simplified to some extent.

[0160] Figure 4 is a schematic flowchart of a multi-channel signal decoding method according to an embodiment of the present application. The method of Figure 4 may be executed by a decoder-side device or a decoder. The decoding method of Figure 4 corresponds to the encoding method of Figure 3. The decoding method of Figure 4 may be used to decode the bitstream obtained by encoding the first channel signal and the second channel signal in the encoding method of Figure 3. The method of Figure 4 includes the following steps.

[0161] 410. Receive a bitstream.

[0162] 420. Based on the bitstream, obtain a downmix signal of the first channel signal and the second channel signal in the multi-channel signal, as well as parameter indication information, where the parameter indication information is used to indicate the encoded target reverberation gain parameters in the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal.

[0163] The parameter indication information can indicate the sub-bands corresponding to the target reverberation gain parameter by using flag bits. For example, each of the first channel signal and the second channel signal includes 10 sub-bands (sub-bands with index numbers from 0 to 9), the parameter indication information includes 10 flag bits, and the 10 flag bits correspond continuously to the 10 sub-bands of each of the multi-channel signals. When the flag bit corresponding to a sub-band is 1, the reverberation gain parameter corresponding to the sub-band is the target reverberation gain parameter that needs to be encoded. When the flag bit corresponding to a sub-band is 0, the reverberation gain parameter corresponding to the sub-band is not the target reverberation gain parameter. Specifically, when the flag bits corresponding to the sub-bands with index numbers from 0 to 5 are 1 and the flag bits corresponding to the sub-bands with index numbers from 6 to 9 are 0, the decoder side only decodes the reverberation gain parameters corresponding to the sub-bands with index numbers from 1 to 5 during decoding.

[0164] 430. Obtain the target reverberation gain parameter from the bit stream according to the parameter indication information.

[0165] 440. Determine the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameter.

[0166] In this application, the target reverberation gain parameter encoded by the encoder can be determined by using the parameter indication information, and then, based on the target reverberation gain parameter, reverberation processing is performed on the corresponding sub-bands of the first channel signal and the second channel signal.

[0167] Before reverberation processing is performed on the first channel signal and the second channel signal based on the target reverberation gain parameter, it should be understood that the decoder side further obtains a decorrelation signal and corrects the decorrelation signal using the target reverberation gain parameter. Then, by using the corrected decorrelation signal, reverberation processing may be further performed on the first channel signal and the second channel signal. Each of the first channel signal and the second channel signal includes 10 sub-bands (sub-bands with index numbers from 0 to 9). When the reverberation gain parameter corresponding to the sub-bands with index numbers from 0 to 5 is the target reverberation gain parameter, the decoder side only obtains the reverberation gain parameter corresponding to the sub-bands with index numbers from 0 to 5 and does not obtain the reverberation gain parameter corresponding to the sub-bands with index numbers from 6 to 10. Therefore, the decoder side performs reverberation processing only on the sub-bands with index numbers from 0 to 5 of the first channel signal and the second channel signal, and does not perform reverberation processing on the sub-bands with index numbers from 6 to 10 of the first channel signal and the second channel signal.

[0168] When the first channel signal and the second channel signal include a left channel signal and a right channel signal, the step of determining the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameter includes the step of determining a decorrelation signal based on the downmix signal and the target reverberation gain parameter of the frame before the current frame, and the step of determining the left channel signal and the right channel signal based on the decorrelation signal and the downmix signal of the current frame.

[0169] For example, the first channel signal and the second channel signal include a left channel signal and a right channel signal. The downmix signal of the current frame is dmx, the downmix signal of the frame previous to the current frame is dmx_pred, and the target downmix gain parameter is gain. Then, based on dmx_pred and gain, a decorrelation signal tmp is first obtained. Then, based on the downmix signal of the current frame and the decorrelation signal, a left channel signal L = dmx + tmp and a right channel signal R = dmx - tmp are obtained.

[0170] Referring to FIGS. 5 and 6, an example of a left channel signal and a right channel signal is used below to describe in detail the entire process of the multi-channel signal encoding method and decoding method in the embodiments of the present application.

[0171] FIG. 5 is a schematic flowchart of a multi-channel signal encoding method according to an embodiment of the present application. In FIG. 5, the multi-channel signal includes a left channel signal and a right channel signal, and the process of encoding the left channel signal and the right channel signal specifically includes the following steps.

[0172] 510. Calculate the spatial parameters of the left channel signal and the spatial parameters of the right channel signal.

[0173] The spatial parameters include reverberation gain parameters corresponding to the subbands of the left channel signal and the right channel signal, as well as other spatial parameters (such as IC, ILD, ITD, and IPD).

[0174] 520. Perform downmixing processing on the left channel signal (represented by L in the figure) and the right channel signal (represented by R in the figure) to obtain a downmix signal.

[0175] Adaptively select the target reverberation gain parameter that needs to be encoded within the reverberation gain parameters corresponding to the subbands of the left channel signal and the right channel signal.

[0176] 540. Quantize the target reverberation gain parameter and the downmix signal separately to obtain a bitstream.

[0177] Figure 6 is a schematic flowchart of a multi-channel signal decoding method according to an embodiment of the present application. In Figure 6, the multi-channel signal includes a left channel signal and a right channel signal. The bitstream generated by the encoding in Figure 5 may be decoded in Figure 6. The decoding process in Figure 6 specifically includes the following steps.

[0178] 610. Obtain the bitstreams of the left channel signal and the right channel signal.

[0179] 620. Decode the bitstream to obtain a downmix signal.

[0180] 630. Obtain the flag information in the bitstream and determine the target reverberation gain parameter that needs to be decoded based on the flag bits of the flag information.

[0181] 640. Decode the reverberation gain parameters corresponding to the subbands for reverberation processing among the left channel signal, the right channel signal, and other spatial parameters (such as IC, ILD, ITD, and IPD).

[0182] 640. Perform subsequent processing (such as smoothing filtering) on the spatial parameters obtained by decoding.

[0183] 650. Perform upmixing processing based on the downmix signal and the reverberation gain parameter obtained by decoding to obtain the left channel signal and the right channel signal.

[0184] After upmixing processing is performed to obtain a left channel signal and a right channel signal, reverberation processing may be separately performed on the left channel signal and the right channel signal based on a coherence signal.

[0185] In the method shown in FIG. 6, reverberation processing is performed on the left channel signal and the right channel signal based on the target reverberation gain parameter obtained by decoding, and reverberation processing may be performed on some subbands of the left channel signal and the right channel signal based on the target reverberation gain parameter, thereby ensuring the quality of the channel signal obtained after the reverberation processing.

[0186] FIG. 7 is a schematic flowchart of a multi-channel signal encoding method according to an embodiment of the present application. The method of FIG. 7 may be performed by an encoder-side device or an encoder. The method of FIG. 7 includes the following steps.

[0187] 710. Determine a downmix signal of a first channel signal and a second channel signal in the multi-channel signal, and reverberation gain parameters corresponding to different subbands of the first channel signal and the second channel signal.

[0188] The present application does not set a limit on the order between the process of generating the downmix signal and the process of generating the reverberation gain parameters corresponding to different subbands of the first channel signal and the second channel signal. The processes may be performed simultaneously or in order.

[0189] Specifically, the downmix signal may be obtained by performing a downmixing process on a first channel signal and a second channel signal. To obtain the spatial parameters of the first channel signal and the second channel signal, a spatial parameter analysis is performed on the first channel signal and the second channel signal. The spatial parameters include reverberation gain parameters corresponding to each subband of the first channel signal and the second channel signal, as well as IC, ILD, ITD, IPD, etc. between the first channel signal and the second channel signal.

[0190] 720. Based on the energy of N subbands of the downmix signal, a target reverberation gain parameter to be encoded within the reverberation gain parameters corresponding to different subbands of the first channel signal and the second channel signal is determined, where N is an integer greater than 0.

[0191] The energy of a plurality of subbands of the downmix signal may be calculated based on the downmix signal itself, or the energy of the downmix signal may be estimated or inferred using the energy of the first channel signal and the energy of the second channel signal. When the energy of the downmix signal is determined using the energy of the first channel signal and the energy of the second channel signal, the calculation process can be simplified to some extent.

[0192] Specifically, based on the energy of N subbands of the downmix signal, J target subbands may be determined from the N subbands. The energy of any subband among the J target subbands is greater than the energy of another subband different from the J target subbands. Both N and J are integers greater than 0, and J is less than N. The reverberation gain parameters corresponding to the J target subbands are determined as the target reverberation gain parameters.

[0193] Based on the energy of each sub - band of the down - mixed signal, a predetermined number of sub - bands are directly selected from all the sub - bands, and the reverberation gain parameters corresponding to the predetermined number of sub - bands are determined as the target reverberation gain parameters. As a result, the reverberation gain parameters that need to be encoded can be selected more flexibly.

[0194] 730. Encode the down - mixed signal and the target reverberation gain parameters.

[0195] In addition, the down - mixed signal may be a wide - band signal or an ultra - wide - band signal. When the down - mixed signal is a wide - band signal, the plurality of sub - bands may be all the sub - bands of the down - mixed signal. When the down - mixed signal is an ultra - wide - band signal, the plurality of sub - bands may be the sub - bands of the down - mixed signal in the wide - band portion.

[0196] In this application, based on the energy of each sub - band of the down - mixed signal, a specific number of sub - bands are directly selected from all the sub - bands. As a result, the reverberation gain parameters that need to be encoded can be selected more flexibly. In addition, compared with the method of determining the reverberation gain parameters corresponding to the sub - bands in a fixed frequency band as the target reverberation gain parameters, the reverberation gain parameters corresponding to several sub - bands that may not be adjacent in the frequency domain can be directly selected as the target reverberation gain parameters.

[0197] FIG. 8 is a schematic flowchart of a multi - channel signal decoding method according to an embodiment of the present application. The method of FIG. 8 may be executed by a decoder - side device or a decoder. The decoding method of FIG. 8 corresponds to the encoding method of FIG. 7. The decoding method of FIG. 8 may be used to decode the bitstream obtained by encoding the first channel signal and the second channel signal in the encoding method of FIG. 7. The method of FIG. 8 includes the following steps.

[0198] 810. Receive the bitstream.

[0199] 820. Based on the bit stream, obtain the downmix signals of the first channel signal and the second channel signal in the multi-channel signal.

[0200] Specifically, first, the bit streams of the first channel signal and the second channel signal are demultiplexed, and then, in order to obtain the downmix signal, the bit stream corresponding to the downmix signal may be decoded.

[0201] 830. Based on the energy of N sub-bands of the downmix signal, determine the encoded target reverberation gain parameters in the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal, where N is an integer greater than 0.

[0202] Specifically, based on the energy of N sub-bands, J target sub-bands may be determined from the N sub-bands. The energy of any sub-band among the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, and both N and J are integers greater than 0, and J is less than N. The reverberation gain parameters corresponding to the J target sub-bands are determined as the target reverberation gain parameters.

[0203] It should be understood that both the encoder side and the decoder side can determine the encoded target reverberation gain parameters in the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal according to the same rule based on the energy of a plurality of sub-bands of the downmix signal. In this way, the encoder side may not need to indicate the encoded reverberation gain parameters in the bit stream, and the decoder side can determine the encoded reverberation gain parameters using the same rule.

[0204] For example, on the encoder side, based on the energies of a plurality of sub-bands of the downmix signal, it is determined that the reverberation gain parameters corresponding to the sub-bands with index numbers from 0 to 5 are the target reverberation gain parameters. The encoder side quantizes the reverberation gain parameters corresponding to the sub-bands with index numbers from 0 to 5, writes the quantized reverberation gain parameters into a bitstream, and transmits the bitstream to the decoder side. After receiving the bitstream, the decoder side similarly determines, based on the energies of a plurality of sub-bands of the downmix signal, that the reverberation gain parameters corresponding to the sub-bands with index numbers from 0 to 5 are the target reverberation gain parameters, and then the decoder side decodes the reverberation gain parameters corresponding to the sub-bands with index numbers from 0 to 5.

[0205] 840. Determine the target reverberation gain parameter based on the bitstream.

[0206] In addition to the target reverberation gain parameter, other spatial parameters encoded on the encoder side, such as IC, ILD, ITD, and IPD, may be obtained from the bitstream.

[0207] 850. Determine the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameter.

[0208] In the present application, on the decoder side, based on the energies of a plurality of sub-bands of the downmix signal, the encoded target reverberation gain parameters within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal can be directly determined. As a result, the bits occupied by the decoder side to transmit the indication information indicating the encoded target reverberation gain parameters are reduced, and the signaling overhead can be reduced to a certain extent.

[0209] Specifically, based on the target reverberation gain parameter, before performing reverberation processing on the first channel signal and the second channel signal, the decoder side further obtains a decorrelation signal and corrects the decorrelation signal using the target reverberation gain parameter (the decorrelation signal may be obtained by delaying the downmix signal). Then, by using the corrected decorrelation signal, reverberation processing may be further performed on the first channel signal and the second channel signal. If each of the first channel signal and the second channel signal includes 10 sub-bands and the reverberation gain parameters corresponding to the sub-bands with index numbers 1, 3, 5, and 7 are the target reverberation gain parameters, the decoder side only obtains the reverberation gain parameters corresponding to the sub-bands with index numbers 1, 3, 5, and 7 and does not obtain the reverberation gain parameters corresponding to the sub-bands with index numbers 2, 4, 6, 8, 9, and 10. Therefore, the decoder side performs reverberation processing only on the sub-bands of the first channel signal and the second channel signal with index numbers 1, 3, 5, and 7, and does not perform reverberation processing on the sub-bands of the first channel signal and the second channel signal with index numbers 2, 4, 6, 8, 9, and 10.

[0210] When the first channel signal and the second channel signal include a left channel signal and a right channel signal, the step of determining the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameter includes the step of determining a decorrelation signal based on the downmix signal and the target reverberation gain parameter of the frame before the current frame, and the step of determining the left channel signal and the right channel signal based on the decorrelation signal and the downmix signal of the current frame.

[0211] Referring to FIGS. 9 and 10, an example of a left channel signal and a right channel signal will be used below to describe in detail the entire process of the multi-channel signal encoding method and decoding method in the embodiments of the present application.

[0212] FIG. 9 is a schematic flowchart of a multi-channel signal encoding method according to an embodiment of the present application. In FIG. 9, the multi-channel signal includes a left channel signal and a right channel signal, and the process of encoding the left channel signal and the right channel signal specifically includes the following steps.

[0213] 910. Calculate the spatial parameters of the left channel signal and the spatial parameters of the right channel signal.

[0214] The spatial parameters include reverberation gain parameters corresponding to the sub-bands of the left channel signal and the right channel signal, as well as other spatial parameters (such as IC, ILD, ITD, and IPD).

[0215] 920. Perform downmixing processing on the left channel signal (represented by L in the figure) and the right channel signal (represented by R in the figure) to obtain a downmix signal.

[0216] 930. Determine the energy of different sub-bands of the downmix signal.

[0217] The energy of the downmix signal may be calculated based on the downmix signal itself, Left channel signal the energy of Right channel signal and may also be estimated or inferred based on the energy of

[0218] 940. Based on the energy of different sub-bands of the downmix signal, adaptively select the target reverberation gain parameters to be encoded within the reverberation gain parameters corresponding to the sub-bands of the left channel signal and the right channel signal.

[0219] 950. Quantize the target reverberation gain parameter and the downmix signal to obtain a bitstream.

[0220] Figure 10 is a schematic flowchart of a multi-channel signal decoding method according to an embodiment of the present application. In Figure 10, the multi-channel signal includes a left channel signal and a right channel signal. The bitstream generated by the encoding in Figure 9 may be decoded in Figure 10. The decoding process in Figure 10 specifically includes the following steps.

[0221] 1010. Obtain the bitstreams of the left channel signal and the right channel signal.

[0222] 1020. Decode the bitstream to obtain a downmix signal.

[0223] 1030. Determine the energy of different subbands of the downmix signal.

[0224] The energy of the downmix signal may be calculated based on the downmix signal itself, Left channel signal the energy of Right channel signal and may be estimated or inferred based on the energy of

[0225] 1040. Based on the energy of different subbands of the downmix signal, adaptively select the subbands of the left channel signal and the right channel signal for reverberation processing.

[0226] 1050. Decode the reverberation gain parameters corresponding to the selected subbands for reverberation processing of the left channel signal and the right channel signal, as well as other spatial parameters (such as IC, ILD, ITD, and IPD).

[0227] To obtain the left-channel signal and the right-channel signal, an upmixing process is performed based on the downmix signal and the reverberation gain parameter obtained by decoding (the reverberation gain parameter is the reverberation gain parameter adjusted on the encoder side).

[0228] After the upmixing process is performed to obtain the left-channel signal and the right-channel signal, reverberation processing may be separately performed on the left-channel signal and the right-channel signal based on the coherence signal.

[0229] In the method shown in FIG. 10, reverberation processing is performed on the left-channel signal and the right-channel signal based on the target reverberation gain parameter obtained by decoding, and reverberation processing may be performed on some subbands of the left-channel signal and the right-channel signal based on the target reverberation gain parameter, thereby ensuring the quality of the channel signal obtained after the reverberation processing.

[0230] The above has described in detail the multi-channel signal encoding method and the multi-channel signal decoding method in the embodiments of the present application with reference to FIGS. 3 to 10. Hereinafter, the encoder and the decoder in the embodiments of the present application will be described with reference to FIGS. 11 to 18. It should be understood that the encoders and decoders in FIGS. 11 to 18 can implement the steps executed by the encoders and decoders in the encoding method and the decoding method in the embodiments of the present application. For the sake of brevity, the following repeated descriptions are appropriately omitted.

[0231] FIG. 11 is a schematic block diagram of an encoder according to an embodiment of the present application. The encoder 1100 in FIG. 11 is a processing unit 1110 configured to determine the downmix signals of the first channel signal and the second channel signal in the multi-channel signal, and the reverberation gain parameters corresponding to different subbands of the first channel signal and the second channel signal, where The processing unit 1110 is further configured to determine a target reverberation gain parameter that needs to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal, The processing unit 1110 is further configured to generate parameter indication information, and the parameter indication information is used by the processing unit 1110 to indicate the sub-bands corresponding to the target reverberation gain parameter, An encoding unit 1120 configured to encode the target reverberation gain parameter, the parameter indication information, and the downmix signal to generate a bitstream is included.

[0232] In the present application, when the first channel signal and the second channel signal are encoded, the reverberation gain parameters corresponding to only some sub-bands of the first channel signal and the second channel signal may be encoded. Compared with the prior art method in which the reverberation gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal need to be encoded, the bit overhead can be reduced to a certain extent, and the encoding efficiency can be improved. Specifically, when the reverberation gain parameters corresponding to some sub-bands are encoded, a large number of saved bits can be used to encode another parameter or allocate more bits to the downmix signal, thereby improving the overall encoding performance.

[0233] The encoder 1100 can correspond to the multi-channel signal encoding method of FIG. 3, and the encoder 1100 can execute the multi-channel signal encoding method of FIG. 3.

[0234] In some cases, in one embodiment, the processing unit 1110 is specifically configured to determine a target reverberation gain parameter based on at least one of the coherence between the energy of the first channel signal and the energy of the downmix signal and the coherence between the energy of the second channel signal and the energy of the downmix signal.

[0235] In some cases, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and the processing unit 1110 is specifically configured to determine a first difference value between the energy of the first channel signal and the energy of the downmix signal, where the first difference value is used to indicate the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins, and when the first difference value is greater than a first threshold value, determine that the reverberation gain parameter corresponding to the sub-band of the first frequency band is the target reverberation gain parameter, where the first frequency band is a part of all the frequency bands of each of the first channel signal and the second channel signal.

[0236] In some cases, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and the processing unit 1110 is specifically configured to determine a second difference value between the energy of the second channel signal and the energy of the downmix signal, where the second difference value is used to indicate the sum of the absolute values of the difference values between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins, and when the second difference value is greater than a second threshold value, determine that the reverberation gain parameter corresponding to the sub-band of the first frequency band is the target reverberation gain parameter, where the first frequency band is a part of all the frequency bands of each of the first channel signal and the second channel signal.

[0237] In some cases, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and the processing unit 1110 is specifically configured to determine a first difference value between the energy of the first channel signal and the energy of the downmix signal, where the first difference value is used to represent the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins, and to determine a second difference value between the energy of the second channel signal and the energy of the downmix signal, where the second difference value is used to represent the sum of the absolute values of the difference values between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins, and when the first difference value is greater than a first threshold value and the second difference value is greater than a second threshold value, to determine that the reverberation gain parameter corresponding to the sub-band of the first frequency band is the target reverberation gain parameter, where the first frequency band is a part of all the frequency bands of each of the first channel signal and the second channel signal.

[0238] In some cases, in one embodiment, the frequency of the first frequency band is lower than the frequency of another frequency band that is different from the first frequency band in the first channel signal and the second channel signal.

[0239] In some cases, in one embodiment, the plurality of frequency bins are within a second frequency band of each of the first channel signal and the second channel signal, and the frequency of the second frequency band is higher than the frequency of another frequency band that is different from the second frequency band in the first channel signal and the second channel signal.

[0240] In some cases, in one embodiment, the processing unit 1110 specifically determines the energy of N sub-bands of the downmix signal and determines M sub-bands from the N sub-bands, where the energy of any sub-band among the M sub-bands is greater than the energy of any sub-band among the N - M sub-bands excluding the M sub-bands, both M and N are integers greater than 0, and M is less than N, and determines, based on the magnitude relationship between the energy of the M sub-bands of the downmix signal and the energy of the N - M sub-bands of the downmix signal, the target reverberation gain parameter.

[0241] In some cases, in one embodiment, the processing unit 1110 specifically determines that when the sum of the energies of the M sub-bands is greater than L times the sum of the energies of the N - M sub-bands, the reverberation gain parameter corresponding to the sub-bands in the first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter, where the first frequency band is part of all the frequency bands of each of the first channel signal and the second channel signal, and L is a real number greater than 0.

[0242] In some cases, in one embodiment, the processing unit 1110 is specifically configured to determine the energy of N sub-bands of the downmix signal and determine M sub-bands from the N sub-bands, where the energy of any sub-band among the M sub-bands is greater than the energy of any sub-band among the N - M sub-bands excluding the M sub-bands. When the index value of the first sub-band among the M sub-bands is smaller than the preset index value, it is determined that the reverberation gain parameter corresponding to the sub-band in the first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter, where the frequency of any frequency bin in the first sub-band is greater than the frequency of any frequency bin in another sub-band among the M sub-bands excluding the first sub-band, and the first frequency band is a part of all the frequency bands of each of the first channel signal and the second channel signal.

[0243] In some cases, in one embodiment, the processing unit 1110 is specifically configured to determine J target sub-bands from N sub-bands, where the energy of any sub-band among the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, both N and J are integers greater than 0, and J is smaller than N. And it is configured to determine the reverberation gain parameter corresponding to the J target sub-bands as the target reverberation gain parameter.

[0244] In some cases, in one embodiment, the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

[0245] FIG. 12 is a schematic block diagram of a decoder according to an embodiment of the present application. The decoder 1200 in FIG. 12 is an acquisition unit 1210 configured to receive a bitstream, The acquisition unit 1210 is further configured to acquire a downmix signal of a first channel signal and a second channel signal in a multi-channel signal, and parameter indication information, based on a bit stream, where the parameter indication information is used to indicate an encoded target reverberation gain parameter in a reverberation gain parameter corresponding to different sub-bands of the first channel signal and the second channel signal. The acquisition unit 1210 is further configured to acquire a target reverberation gain parameter from the bit stream according to the parameter indication information. A processing unit 1220 configured to determine the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameter. It includes.

[0246] In the present application, the target reverberation gain parameter encoded by the encoder can be determined using the parameter indication information, and then, based on the target reverberation gain parameter, reverberation processing is performed on the corresponding sub-bands of the first channel signal and the second channel signal.

[0247] Decoder 1200 can correspond to the multi-channel signal decoding method of FIG. 4, and the decoder 1200 can execute the multi-channel signal decoding method of FIG. 4.

[0248] FIG. 13 is a schematic block diagram of an encoder according to an embodiment of the present application. The encoder 1300 in FIG. 13 is A processing unit 1310 configured to determine a downmix signal of a first channel signal and a second channel signal in a multi-channel signal, and a reverberation gain parameter corresponding to different sub-bands of the first channel signal and the second channel signal. The processing unit 1310 is further configured to determine target reverberation gain parameters to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal based on the energy of N sub-bands of the downmix signal, where N is an integer greater than 0, the processing unit 1310, an encoding unit 1320 configured to encode the downmix signal and the target reverberation gain parameters and includes.

[0249] In this application, based on the energy of each sub-band of the downmix signal, a specific number of sub-bands are directly selected from all sub-bands, and as a result, the reverberation gain parameters that need to be encoded can be selected more flexibly.

[0250] The encoder 1300 can correspond to the Multi channel signal encoding method of FIG. 7, and the encoder 1300 can execute the Multi channel signal encoding method of FIG. 7.

[0251] In some cases, in one embodiment, the processing unit 1310 is specifically to determine J target sub-bands from N sub-bands, where the energy of any sub-band among the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, both N and J are integers greater than 0, and J is less than N, and to determine the reverberation gain parameters corresponding to the J target sub-bands as the target reverberation gain parameters.

[0252] FIG. 14 is a schematic block diagram of a decoder according to an embodiment of the present application. The decoder 1400 in FIG. 14 includes a first acquisition unit 1410 configured to receive a bitstream, A first processing unit 1420 configured to determine downmix signals of a first channel signal and a second channel signal in a multi-channel signal based on a bitstream; A second processing unit 1430 configured to determine encoded target reverberation gain parameters in reverberation gain parameters corresponding to different subbands of the first channel signal and the second channel signal based on the energy of N subbands of the downmix signal, where N is an integer greater than 0; A third processing unit 1440 configured to determine target reverberation gain parameters based on a bitstream; A fourth processing unit 1450 configured to determine the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameters; including.

[0253] In this application, on the decoder side, based on the energy of a plurality of subbands of the downmix signal, the encoded target reverberation gain parameters in the reverberation gain parameters corresponding to different subbands of the first channel signal and the second channel signal can be directly determined. As a result, the bits occupied by the decoder side to transmit the indication information indicating the encoded target reverberation gain parameters are reduced, and the signaling overhead can be reduced to a certain extent.

[0254] The decoder 1400 can correspond to the multi-channel signal decoding method in FIG. 8, and the decoder 1400 can execute the multi-channel signal decoding method in FIG. 8 of the multi-channel signal decoding method.

[0255] In some cases, in one embodiment, the first processing unit 1420Specifically, it is to determine J target sub-bands from N sub-bands based on the energies of the N sub-bands, where the energy of any sub-band among the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, both N and J are integers greater than 0, and J is less than N, and to determine the reverberation gain parameters corresponding to the J target sub-bands as target reverberation gain parameters.

[0256] FIG. 15 is a schematic block diagram of an encoder according to an embodiment of the present application. The encoder 1500 in FIG. 15 includes a memory 1510 configured to store a program, a processor 1520 configured to execute the program. When the program is executed, the processor 1520 determines the downmix signals of the first channel signal and the second channel signal in the multi-channel signal, as well as the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal, determines the target reverberation gain parameters that need to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal, generates parameter indication information, where the parameter indication information is used to indicate the sub-bands corresponding to the target reverberation gain parameters, and encodes the target reverberation gain parameters, the parameter indication information, and the downmix signal to generate a bitstream. including.

[0257] In the present application, when the first channel signal and the second channel signal are encoded, the reverberation gain parameters corresponding to only some sub-bands of the first channel signal and the second channel signal may be encoded. Compared with the prior art method in which the reverberation gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal need to be encoded, the bit overhead can be reduced to some extent, and the encoding efficiency can be improved. Specifically, when the reverberation gain parameters corresponding to some sub-bands are encoded, a large number of saved bits can be used to encode another parameter or allocate more bits to the downmix signal, thereby improving the overall encoding performance.

[0258] The encoder 1500 can correspond to the channel signal encoding method of FIG. 3, and the encoder 1500 can Multi execute the channel signal encoding method of FIG. 3. Multi The encoder 1500 can execute the channel signal encoding method of FIG. 3.

[0259] In some cases, in one embodiment, the processor 1520 is specifically configured to determine the target reverberation gain parameter based on at least one of the coherence between the energy of the first channel signal and the energy of the downmix signal and the coherence between the energy of the second channel signal and the energy of the downmix signal.

[0260] In some cases, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and specifically, the processor 1520 is configured to determine a first difference value between the energy of the first channel signal and the energy of the downmix signal, where the first difference value is used to indicate the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins, and when the first difference value is greater than a first threshold value, to determine that the reverberation gain parameter corresponding to the sub-band of the first frequency band is the target reverberation gain parameter, where the first frequency band is a part of all the frequency bands of each of the first channel signal and the second channel signal.

[0261] In some cases, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and specifically, the processor 1520 is configured to determine a second difference value between the energy of the second channel signal and the energy of the downmix signal, where the second difference value is used to indicate the sum of the absolute values of the difference values between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins, and when the second difference value is greater than a second threshold value, to determine that the reverberation gain parameter corresponding to the sub-band of the first frequency band is the target reverberation gain parameter, where the first frequency band is a part of all the frequency bands of each of the first channel signal and the second channel signal.

[0262] In some cases, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and the processor 1520 is specifically configured to determine a first difference value between the energy of the first channel signal and the energy of the downmix signal, where the first difference value is used to indicate the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins, and to determine a second difference value between the energy of the second channel signal and the energy of the downmix signal, where the second difference value is used to indicate the sum of the absolute values of the difference values between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins, and when the first difference value is greater than a first threshold value and the second difference value is greater than a second threshold value, to determine that the reverberation gain parameter corresponding to the sub-band of the first frequency band is the target reverberation gain parameter, where the first frequency band is a part of all the frequency bands of each of the first channel signal and the second channel signal.

[0263] In some cases, in one embodiment, the frequency of the first frequency band is lower than the frequency of another frequency band different from the first frequency band in the first channel signal and the second channel signal.

[0264] In some cases, in one embodiment, the plurality of frequency bins are within a second frequency band of each of the first channel signal and the second channel signal, and the frequency of the second frequency band is higher than the frequency of another frequency band different from the second frequency band in the first channel signal and the second channel signal.

[0265] In some cases, in one embodiment, the processor 1520 is specifically configured to determine the energy of N sub-bands of the downmix signal and determine M sub-bands from the N sub-bands, where the energy of any sub-band among the M sub-bands is greater than the energy of any sub-band among the N-M sub-bands excluding the M sub-bands, both M and N are integers greater than 0, and M is less than N, and to determine a target reverberation gain parameter based on the magnitude relationship between the energy of the M sub-bands and the energy of the N-M sub-bands.

[0266] In some cases, in one embodiment, the processor 1520 is specifically configured to determine that the reverberation gain parameter corresponding to the sub-bands in the first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter when the sum of the energies of the M sub-bands is greater than L times the sum of the energies of the N-M sub-bands, where the first frequency band is a part of all the frequency bands of each of the first channel signal and the second channel signal, and L is a real number greater than 0.

[0267] In some cases, in one embodiment, the processor 1520 is specifically configured to determine the energy of N sub-bands of the downmix signal, and to determine M sub-bands from the N sub-bands, where the energy of any sub-band among the M sub-bands is greater than the energy of any sub-band among the N - M sub-bands excluding the M sub-bands; and when the index value of the first sub-band among the M sub-bands is smaller than the preset index value, to determine that the reverberation gain parameter corresponding to the sub-band of the first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter, where the frequency of any frequency bin within the first sub-band is greater than the frequency of any frequency bin within another sub-band among the M sub-bands excluding the first sub-band, and the first frequency band is part of all the frequency bands of each of the first channel signal and the second channel signal.

[0268] In some cases, in one embodiment, the processor 1520 is specifically configured to determine the energy of N sub-bands of the downmix signal, and to determine J target sub-bands from the N sub-bands based on the energy of the N sub-bands, where the energy of any sub-band among the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, both N and J are integers greater than 0, and J is smaller than N; and to determine the reverberation gain parameter corresponding to the J target sub-bands as the target reverberation gain parameter.

[0269] In some cases, in one embodiment, the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

[0270] FIG. 16 is a schematic block diagram of a decoder according to an embodiment of the present application. The decoder 1600 in FIG. 16 is A memory 1610 configured to store a program, A processor 1620 configured to execute the program. When the program is executed, the processor 1620 is configured to receive a bitstream, obtain a downmix signal of a first channel signal and a second channel signal in a multi-channel signal, and parameter indication information based on the bitstream, where the parameter indication information is used to indicate an encoded target reverberation gain parameter in a reverberation gain parameter corresponding to different sub-bands of the first channel signal and the second channel signal, obtain the target reverberation gain parameter from the bitstream according to the parameter indication information, and determine the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameter. Including.

[0271] In this application, the target reverberation gain parameter encoded by the encoder can be determined using the parameter indication information, and then, based on the target reverberation gain parameter, reverberation processing is performed on the corresponding sub-bands of the first channel signal and the second channel signal.

[0272] The decoder 1600 can correspond to the multi-channel signal decoding method of FIG. 4, and the decoder 1600 can execute the multi-channel signal decoding method of FIG. 4.

[0273] FIG. 17 is a schematic block diagram of an encoder according to an embodiment of the present application. The encoder 1700 in FIG. 17 includes A memory 1710 configured to store a program, A processor 1720 configured to execute a program, which, when executed, causes the processor 1720 to determine a downmix signal of a first channel signal and a second channel signal in a multi-channel signal, as well as reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal, and to determine a target reverberation gain parameter to be encoded within the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal based on the energy of N sub-bands of the downmix signal, where N is an integer greater than 0, and to encode the downmix signal and the target reverberation gain parameter. The processor 1720 is configured to perform the above operations. including.

[0274] In the present application, based on the energy of each sub-band of the downmix signal, a specific number of sub-bands are directly selected from all the sub-bands, as a result, the reverberation gain parameters that need to be encoded can be selected more flexibly.

[0275] The encoder 1700 can correspond to the channel signal encoding method in FIG. 7. Multi The encoder 1700 can execute the channel signal encoding method in FIG. 7. Multi The encoder 1700 can execute the channel signal encoding method in FIG. 7.

[0276] In some cases, in one embodiment, the processor 1720 is specifically configured to determine J target sub-bands from N sub-bands based on the energy of the N sub-bands, where the energy of any sub-band among the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, and both N and J are integers greater than 0, and J is less than N. The processor 1720 is configured to determine the reverberation gain parameters corresponding to the J target sub-bands as the target reverberation gain parameters.

[0277] FIG. 18 is a schematic block diagram of a decoder according to an embodiment of the present application. The decoder 1800 in FIG. 18 includes a memory 1810 configured to store a program, and a processor 1820 configured to execute the program. When the program is executed, the processor 1820 receives a bitstream, determines downmix signals of a first channel signal and a second channel signal in a multi-channel signal based on the bitstream, determines encoded target reverberation gain parameters in reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal based on the energy of N sub-bands of the downmix signal, where N is an integer greater than 0, determines target reverberation gain parameters based on the bitstream, and determines the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameters. and includes.

[0278] In the present application, on the decoder side, encoded target reverberation gain parameters in reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal can be directly determined based on the energy of a plurality of sub-bands of the downmix signal. As a result, the bits occupied by the decoder side to transmit indication information indicating the encoded target reverberation gain parameters are reduced, and the signaling overhead can be reduced to a certain extent.

[0279] The decoder 1800 can correspond to the multi-channel signal decoding method in FIG. 8, and the decoder 1800 can execute the multi-channel signal decoding method in FIG. 8 of the multi-channel signal decoding method.

[0280] In some cases, in one embodiment, the processor 1820 is specifically configured to determine J target sub-bands from N sub-bands based on the energy of the N sub-bands, where the energy of any sub-band among the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, and both N and J are integers greater than 0, and J is less than N, and to determine the reverberation gain parameters corresponding to the J target sub-bands as the target reverberation gain parameters.

[0281] Those skilled in the art will recognize that, in combination with the examples described in the embodiments disclosed herein, the units and algorithm steps may be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether the functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use various methods to implement the functions described for each specific application, but the implementation should not be considered to exceed the scope of this application.

[0282] For the sake of convenience and brevity of description, those skilled in the art should clearly understand that for the detailed operation processes of the above systems, devices, and units, reference may be made to the corresponding processes in the above method embodiments, and details will not be described again herein.

[0283] In some embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods may be implemented in other ways. For example, the described device embodiments are merely examples. For example, the unit division is only a logical function division, and in actual implementation forms, other divisions may be used. For example, a plurality of units or components may be combined or integrated into another system, or some functions may be ignored or not executed. In addition, the shown or described mutual coupling or direct coupling or communication connection may be implemented by using some interfaces. The indirect coupling or communication connection between devices or units may be implemented in electrical, mechanical, or other forms.

[0284] The units described as separate parts may or may not be physically separated, and the parts shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected based on actual requirements to achieve the purpose of the solution of the embodiment.

[0285] In addition, the functional units in the embodiments of this application may be integrated into one processing unit, or each of the units may physically exist alone, or two or more units may be integrated into one unit.

[0286] When the function is implemented in the form of a software functional unit and sold or used as an independent product, the function may be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, may also be implemented in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for instructing a computer device (which may be a personal computer, a server, a network device, etc.) to execute all or some of the steps of the method described in the embodiments of this application. The aforementioned storage medium includes any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0287] The above description is only a specific implementation form of this application and does not limit the protection scope of this application. Any deformation or substitution that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should fall within the protection scope of this application. Therefore, the protection scope of this application should follow the protection scope of the claims.

Explanation of Reference Signs

[0288] 1100 Encoder 1110 Processing Unit 1120 Encoding Unit 1200 Decoder 1210 Acquisition Unit 1220 Processing Unit 1300 Encoder 1310 Processing Unit 1320 Encoding Unit 1400 Decoder 1410 First Acquisition Unit 1420 First Processing Unit 1430 Second Processing Unit 1440 Third processing unit 1450 Fourth processing unit 1500 Encoder 1510 Memory 1520 Processor 1600 Decoder 1610 Memory 1620 Processor 1700 Encoder 1710 Memory 1720 Processor 1800 Decoder 1810 Memory 1820 Processor

Claims

1. A multi-channel signal decoding method, comprising: receiving a bitstream, wherein the bitstream includes a target reverberation gain parameter, parameter indication information, and a downmix signal; obtaining the downmix signal based on the bitstream, wherein the downmix signal corresponds to a channel signal of a multi-channel signal, and the channel signal includes a plurality of subbands; obtaining the parameter indication information from the bitstream, wherein the parameter indication information indicates whether the target reverberation gain parameter is applied to only a part of the plurality of subbands or to all of the plurality of subbands; when the parameter indication information indicates that the target reverberation gain parameter is applied to only the part of the plurality of subbands, obtaining a reverberation gain parameter corresponding to each of the part of the plurality of subbands; obtaining a channel signal reconstructed according to the downmix signal and the reverberation gain parameter; A multi-channel signal decoding method comprising the above steps.

2. The multi-channel signal decoding method according to Claim 1, wherein the parameter indication information is a flag represented by 1 bit.

3. The multi-channel signal decoding method according to Claim 1, wherein the plurality of subbands have consecutive indexes.

4. The multi-channel signal decoding method according to Claim 3, wherein the part of the plurality of subbands has consecutive indexes.

5. The multi-channel signal decoding method according to Claim 4, wherein the highest index of the part of the plurality of subbands is lower than the lowest index of another part of the plurality of subbands.

6. The multi-channel signal decoding method according to claim 4, wherein the lowest index of the part of the plurality of sub-bands is higher than the highest index of the other part of the plurality of sub-bands.

7. The multi-channel signal decoding method according to claim 3, wherein the part of the plurality of sub-bands is predefined.

8. A multi-channel signal decoder, comprising: a memory configured to store processor-executable instructions; a processor operably coupled to the memory, the processor being configured to execute the processor-executable instructions that cause the multi-channel signal decoder to perform the method according to any one of claims 1 to 7; and a multi-channel signal decoder comprising the same.

9. A computer-readable storage medium having a program recorded thereon, the program causing a computer to perform the method according to any one of claims 1 to 7.

10. A computer program stored in a medium configured to cause a computer to perform the method according to any one of claims 1 to 7.

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